The present invention relates to auger discharge control and more particularly to a flow control spout for an auger, especially the unloading auger of a combine harvester.
Grain or seed is delivered from a combine harvester to the box of a grain truck by a delivery auger on the combine. The auger has a discharge at the end of the auger tube through which the grain is delivered. Because the grain is delivered at a high flow rate, there is a considerable spreading of the grain or seed as it leaves the auger discharge. This in turn leads to xe2x80x9csplashxe2x80x9d, spillage and wind loss. This may be controlled by a spout according to international patent application PCT/CA 98/00760. In use the spout is attached to the end of the auger to provide containment of the grain flow. It includes a chute having a receiving opening larger than the auger tube discharge opening and an outlet opening smaller than the receiver opening. A convergent peripheral wall extends from the inlet opening towards the outlet opening. When mounted on the auger tube, the receiving opening confronts the auger tube discharge opening and the peripheral wall slopes outwardly and downwardly from the end of the auger tube and under the discharge opening.
The sloping peripheral wall intercepts flow from the auger discharge, and redirects the flow to a direction with an outward component. This concentrates the flow from the auger without causing it to back up. In most cases, frusto-conical extensions are mounted on the chute as described in the application referenced above.
If, through inadvertence of an operator or any other cause, grain or seed is allowed to rise to the level of the spout discharge, the spout discharge may become closed, allowing the grain or seed to build up in the spout and then the auger. This will overload the auger and cause damage to the auger and its drive.
Another potential problem may arise if the spout comes into contact with an external object. For example, if the spout is positioned too low with respect to a truck being loaded and the truck hits the spout, damage may be caused to the spout, the auger or the truck.
The present invention is concerned with improvements in the spout that address these concerns.
According to one aspect of the present invention there is provided a spout for an auger having an auger tube with an outer end and an auger tube discharge opening adjacent the outer end, the spout comprising:
a chute having:
a receiving opening;
an outlet opening; and
a convergent peripheral wall extending from the inlet opening towards the outlet opening;
an overflow opening in the peripheral wall; and
a chute mount for mounting the chute on the auger tube with the receiving opening confronting the auger tube.
If the level of the material being conveyed rises to an undesirable level inside the chute for any reason, the excess will flow out of the overflow, preventing or delaying filling of the auger and giving the operator the opportunity to situation, either by removing a blockage or shutting down the auger.
The overflow is positioned out of the normal flow path of the material being conveyed, so that material is not lost through the overflow. It may be an outer overflow in an outwardly sloping outer side of the peripheral wall or an inner overflow in the inner side of a discharge collar forming the lowermost part of the peripheral wall, around the outlet opening. In preferred embodiments, both overflows are used.
The discharge collar is preferably frusto-conical. In use, the inner side of the chute intercepts the flow out of the auger discharge and directs it outwardly where it impinges upon and swirls about the inside of the collar to discharge downwardly from the spout.
To avoid the loss of material through the inner overflow, the peripheral wall may include a lip extending forwardly at the top of the discharge collar, over the inner overflow.
The inner overflow opening provides overflow capacity additional to that of the outer overflow and also an early visual warning to an operator of an overflow condition. This early warning can be augmented by placing a sensor in the inner overflow, for example a microswitch actuator at the bottom edge, to detect the onset of an overflow over the bottom edge.
The ingress of material into the chute through the outer overflow opening, high wind conditions and overshoot of material from the auger through the outer overflow can be concerns. These can be dealt with by providing a shield across the opening. This may be spaced sufficiently from the peripheral wall of the chute that there is no undue restriction of flow. Alternatively, the shield may be sufficiently light weight and freely movable that free flow is not impeded.
According to another aspect of the present invention there is provided a spout for an auger having an auger tube with an auger tube discharge opening on a bottom side of the auger tube, the spout comprising:
a chute having:
a receiving opening;
an outlet opening; and
a convergent peripheral wall extending from the inlet opening towards the outlet opening;
a chute mount for mounting the chute on the auger tube for rotation about the auger tube from a normal position in which the receiving opening confronts the auger tube discharge opening and the peripheral wall depends from the auger tube, and a released position in which the peripheral wall extends laterally from the auger tube; and
a chute centring device for biasing the spout to the normal position.
With this arrangement, engagement of the spout with an external object, for example a truck box, will rotate the spout to a sideways orientation to clear the obstruction with minimal, and preferably no, damage. The chute will automatically return to the normal position once it is released from the external engagement.
In preferred embodiments, the chute mount includes a substantially cylindrical hood for engagement over the outer end of the auger tube. The chute centring device preferably acts as a retainer holding the hood in place on the tube. The centring device may include a band clamped onto the auger tube and an end flange on the chute to engage the band and limit the travel of the chute along the auger tube. One or more resilient elements, for example springs or elastomeric straps, connect the band and the end flange to bias the chute to the normal position.